1. Field of the Invention
The present invention relates generally to the field of electrical discharge weapons of the type which propel a pair of wire-tethered darts to impact a remote target. The invention herein relates more specifically to a wire-tethered dart cartridge which employs potential energy in the form of a coiled spring to impart kinetic energy to the darts to propel them toward a target.
2. Background Art
U.S. Pat. No. 3,803,463 discloses an apparatus for connecting a disabling electrical power supply to a remote animal target by means of dart(s) and trailing wire(s). A prior art reference in U.S. Pat. No. 5,654,867 describes the use of gases expanding from a pyrotechnic explosion to propel a pair of electrically opposed darts from such an electrical discharge weapon.
The most relevant prior art reference appears to be U.S. Pat. No. 5,078,117 which discloses the use of the sudden release of pressurized gas to propel a ballistic device. The sudden release of pressurized gas is effective in propelling ballistic devices over limited distances. Industry currently uses this claimed method of suddenly releasing pressurized gas to propel darts from an electrical discharge weapon. The use of such a propulsion technique in an electrical discharge weapon against a remote target, is beneficial because the weapon is not classified as a firearm. Thus, it may be used by civilians for self defense without restrictions and regulations that would otherwise be required by state or federal law if the weapon were classified as a firearm. Even though a pyrotechnic device is used to penetrate the container of the pressurized gas, because the ballistic devices (i.e., darts) are not propelled by the energy of the pyrotechnic device, the definition of a firearm is avoided under the various applicable laws.
Unfortunately, the use of the sudden release of a pressurized gas to propel wire-tethered darts does introduce certain unpredictable results. Principally, for a number of reasons, the accuracy and repeatability of the ballistic results imparted to the darts are less than would be desirable. One reason for this unpredictability is the method of releasing the gas. More specifically, a pyrotechnic device is electrically ignited to propel a pointed penetrator toward the container of the pressurized gas and rupture the container. The inexact nature of the ignition, the penetrator and the container, as well as the gas pressure itself, contribute to variation in the precise geometry of the rupture. As a result, the escaping gas does not follow a predictable path in exiting the container. The gas may therefore impact each of the two separate darts differently. Moreover, the gas flow is likely to be turbulent as pressure builds behind and around each dart, particularly as each dart exits the cartridge. All of these effects produce ballistic inaccuracy which makes it less likely that the darts will hit the intended target at all, let alone hit the target at specific locations where the electric discharge can be effective.
Thus, there is a need to find an alternative wire-tethered dart propulsion system which has the advantage of not being classified as a firearm, but which does not rely on sudden release of pressurized gas that is likely to diminish the accuracy of the weapon.
The present invention meets the aforementioned need by providing a dual wire-tethered dart cartridge for electrical discharge weapons wherein the sudden force needed to propel the darts toward a remote target is derived from a source of energy which does not rely on the use of a pressurized gas. While a pyrotechnic device is used to release the energy, like the prior art, the pyrotechnic-derived energy does not propel the darts. Therefore, the invention also provides the advantage of not being classified as a firearm under state and federal law. Furthermore, the propulsive force is derived from potential energy stored in at least one coiled spring having an arm which impacts the dart with sufficient force to propel the dart a desired distance toward a remote target. In a preferred embodiment disclosed herein, the spring is formed on two interconnected coils, each end of the spring wire extending from a respective coil and forming an impact arm for striking the back of the dart. The arms are maintained in a tensioned configuration by retention pistons each of which is connected to a pyrotechnic device. When an electrical voltage is applied to the pyrotechnic devices, the ignition forces the pistons to move to suddenly release the arms. The potential energy in the springs then forces the arms to rotate around their respective coils at high speed and impact the respective darts.
Because the invention does not require penetration of a pressurized gas container, the uncertainties of the gas container penetration and the gas flow turbulence are entirely avoided. Therefore, the transfer of energy from the spring to the darts is more predictable and repeatable and easier to adjust from cartridge to cartridge during manufacture. The result is a more accurate ballistic performance as compared to the prior art gas propelled system.
It is therefore a principal object of the present invention to provide a cartridge having wire-tethered darts for use in an electrical discharge weapon wherein the darts are propelled toward a remote target by the impact of an arm of a coiled spring released upon activation of the weapon.
It is another object of the invention to provide a gasless dart propulsion system in a cartridge having wire-tethered darts for use in an electrical discharge weapon.
It is yet another object of the invention to provide a propulsion system for wire-tethered darts in an electrical discharge weapon system wherein the darts are propelled by a spring instead of a sudden release of a pressurized gas from a penetrated container.
It is yet another object of the invention to provide an electrically activated cartridge for propelling darts toward a remote target in an electrical discharge weapon wherein pyrotechnic devices are employed to release tensioned spring arms to impact the darts to impart energy thereto.